1. Field of the Invention
The present invention relates generally to the art of non-slip coatings, and more particularly to non-slip coatings for molded articles, such as trays. Still more particularly, the present invention relates to providing permanent non-slip coatings during the molding process for the article to be produced.
2. Description of the Prior Art
Non-slip coatings have been known for many years for a variety of finished industrial and consumer products. For example, articles can be painted with a finish coat which may include abrasive materials, such as silica, sand or other granular materials. These granular materials, along with the resin binder, provide a rough surface which provides some non-slip characteristics. It is also known that non-slip materials such as rubber mats, cork sheets or other materials can be laminated to the object to which non-slip characteristics are to be added.
Non-slip properties for molded articles are desirable for many different applications. One typical application is trays, such as those trays used in restaurants, cafeterias, cocktail lounges, etc. Such trays are usually made by molding a fiberglass reinforced plastic and finishing by sanding and other conventional techniques. Such trays are usually quite slick, especially when they are wet. The resultant problems are obvious, and those involved in the tray art have searched for many years for a way of providing a non-slip surface on the trays.
One approach has been to glue a thin, textured rubber mat over the surface of the tray, using a suitable rubber adhesive. These trays do provide improved non-slip performance, but they suffer from several serious disadvantages. First, the process for preparing the trays is time-consuming, labor intensive, and expensive. Second, the rubber mat coating or the adhesive may be exposed to solvents which will deteriorate the rubber or the adhesive. For example, salad oil has a tendency to delaminate such rubber mats. Third, such trays require cleaning, and if used in food or drink service applications, they must be sanitized, which means subjecting the trays to high temperatures and/or pressures. Such cleaning will also result in rapid deterioration of the rubber mat.
Abrasive fill coatings can also deteriorate under the aforementioned conditions and are also prone to mechanical abrasion during use, which has a tendency to remove the binder coating over the granular particles, leading eventually to degradation of the non-slip properties of the coated product.
Non-slip properties are desirable in applications other than trays. For example, many boat parts are now prepared from molded, fiberglass-reinforced plastic, and it would be desirable to provide a non-slip surface therefor. Such a finish would reduce the likelihood of a person inadvertently slipping when walking on the piece. Other examples of articles for which a non-slip finish would be desirable are pads for office supplies and bathroom fixtures such as tubs and shower stalls.
A method for preparing long-lasting, non-slip surfaces which is economical and fast and which produces products of improved quality would represent a substantial advance in the art.
As used herein, the term "non-slip" surface means a surface upon which articles placed will be prevented from or will have a reduced tendency for sliding.